When aiming a target with a weapon, such as a shooting weapon, specialized weapon attachments such as a digital imaging weapon sight, a day view optic (direct view optic) and the like, are used. In one form, digital imaging weapon sights are mounted onto shooting weapons (such as guns, rifles, and the like). More specifically, the digital imaging weapon sights are mounted onto the shooting weapons in front of day view optics so that thermal imagery (taken by the digital imaging weapon sights) may be used for aiming targets without either removing the day view optics or zeroing the digital imaging weapon sights. Such an arrangement of the digital imaging weapon sights in front of the day view optics, as mounted onto the shooting weapons, is typically referred to as a clip-on arrangement.
Typically, in a clip-on arrangement, a digital imaging weapon sight is designed to have a unity magnification (i.e., no magnification of a thermal image generated by the digital imaging weapon sight) to ensure that line of sight to a target is not perturbed. Further, the line of sight to the target is taken to be a red dot present in the day view optic. Typically, the red dot, which is an indication feature of the day view optic, is generated by an optical unit, such as a laser, configured within the day view optic, and is projected through the day view optic towards the target being aimed in order to precisely shoot the target.
Further, for shooting the target more precisely, a typical digital imaging weapon sight is provided with an electronic zoom mode. The electronic zoom mode is utilized to magnify a thermal image of a target being aimed. Magnification of the thermal image of the target being aimed enables finer details to be recognized by a user of the shooting weapon that employs the digital imaging weapon sight. However, the magnification of the thermal image of the target being aimed makes the electronic zoom mode incompatible with the clip-on arrangement for targeting purposes.
As an example, FIGS. 1-3 illustrate schematic diagrams for aiming a target using a conventional electronic zoom mode of a digital imaging weapon sight (not shown) that is configured adjacent to a direct view optic (not shown) of a shooting weapon (not shown). In FIG. 1, a thermal image 100 of the target is shown when the conventional electronic zoom mode is not initiated. The thermal image 100, as formed by the digital imaging weapon sight, may be made visible to a user through the direct view optic mounted on the shooting weapon. As further depicted in FIG. 1, the thermal image 100 is shown to include a bullet impact point 110, directly pointing on the target being aimed. Specifically, the bullet impact point 110 is a pictorial representation on the thermal image 100 that signifies a position where a bullet of the shooting weapon will physically impact the target. Furthermore, FIG. 1 depicts a red dot 120 of the direct view optic that falls on the thermal image 100, when the red dot 120 is projected towards the target. For accurate aiming, the red dot 120 needs to be aligned with a reticle of the digital imaging weapon sight.
When the user desires to view finer details of the target, the electronic zoom mode of the digital imaging weapon sight is initiated/activated. The digital imaging weapon sight then tends to magnify (zoom) the thermal image 100 about a physical center 130 of a display of the thermal image 100. FIG. 2 depicts a magnified form of the thermal image 100 of the target being aimed. Thereafter, when the thermal image 100 is viewed through the direct view optic, the alignment of the red dot 120 present on the thermal image 100 is found to be changed with respect to the reticle of the digital imaging weapon sight. Specifically, the alignment of the red dot 120 on the thermal image 100 changes, as the magnification of the thermal image 100 occurs about the physical center 130 of the display of the thermal image 100. Accordingly, when the target is re-aimed, the bullet impact point 110 falls off the magnified thermal image 100, as depicted in FIG. 3. Therefore, magnification of the thermal image 100 of the target being aimed makes the conventional electronic zoom mode incompatible with the clip-on arrangement of the digital imaging weapon sight. Hence, it becomes difficult to aim the target precisely, while using the electronic zoom mode of the digital imaging weapon sight.
Accordingly, there is a need for calibrating an electronic zoom mode of a weapon sight (such as a digital imaging weapon sight), in a manner wherein the electronic zoom mode becomes compatible with the clip-on arrangement of the weapon sight configured in front of a day (direct) view optic mounted on a weapon, while a target is being aimed.